This invention generally relates to the art of electrical connectors and, particularly, to a terminal module for an electrical connector.
A typical electrical connector includes some form of dielectric housing which mounts a plurality of conductive terminals. Various methods are used to mount the terminals in or on the housing. One method is to insert the terminals into preformed terminal-receiving passages in the housing either one terminal at a time or all of the terminals on a strip in a xe2x80x9cgangxe2x80x9d insertion. Another method is to mold a dielectric plastic insert around portions of a plurality of terminals to form a terminal module or subassembly. This module then is mounted in a cavity in the dielectric connector housing.
A significant problem with overmolded terminal modules as described above is that the plastic material is overmolded about substantial portions of the terminals and effectively decreases the impedance through the terminal module. This decrease in impedance can reduce the signal strength due to signal reflection. Little has been done with prior art overmolded terminal modules to prevent this decrease in impedance. The present invention is directed to a simple solution to this impedance problem in an overmolded terminal module.
An object, therefore, of the invention is to provide a new and improved terminal module for use in an electrical connector.
In the exemplary embodiment of the invention, the terminal module includes a plurality of terminals arranged in a generally parallel side-by-side array. Each terminal includes a pair of opposite end sections such as contact and/or termination sections. A pair of holding sections are located respectively adjacent to and inside the end sections. A central section is located between the holding sections. A dielectric plastic housing is overmolded about the holding sections of the terminals leaving the opposite end sections of the terminals exposed. The overmolded housing leaves a substantial portion of the central section of each terminal exposed to reduce the loss of impedance through the terminal module.
According to one aspect of the invention, the central section of each terminal is generally rectangular in cross-section to define a top surface, a bottom surface and a pair of side surfaces. The overmolded housing leaves at least the top surface exposed. As disclosed herein, the overmolded housing leaves the top surface and side surfaces exposed while supporting the bottom surface of the terminal central section.
According to another aspect of the invention, the central section of each terminal can be considered as having a given thickness, with the top of the terminal being exposed by the overmolded housing and the bottom of the terminal being supported by the overmolded housing. A trough is formed in the overmolded housing between the central sections of adjacent terminals. The trough has a depth extending beyond the thickness of the central section, i.e., below the bottom of the terminal.
According to a further aspect of the invention, the terminals are elongated, and the length of the central section of each terminal is greater than 30 per cent of to the combined lengths of the terminal sections within the housing.
Other objects, features and advantages of the invention will be apparent from the following detailed description taken in connection with the accompanying drawings.